MANI'S MICROBIOLOGY

·        Viruses are obligate intracellular parasites, infects all life forms on earth. ·        Host range of viruses vary from a Bacteria to a huge eukaryote. Plant viruses ·        Infects plants. ·        Mostly RNA as the genetic material, single or double-stranded, majority are rod-shaped, size ranges from 300-500nm. ·        Tobacco mosaic virus is a plant virus that has single-stranded RNA as the material. ·        Double-stranded DNA as genetic material is the cauliflower mosaic virus. Animal viruses ·        Infects animals. ·        Major are DNA, helical and icosahedral, Ebola virus is long like a thread ·        Genetic material of animal viruses is made of double-stranded DNA or RNA, si...

  Ø   Structurally viral particles are simple and minute in nature. Ø   A wide diversity of shapes and sizes have been observed. Ø   The viruses are measured in units of nanometre (nm) which is one-thousandth part of a micrometre or a one-millionth part of a millimetre. An Angstrom unit (A) is one-tenth of a nm. Ø   Most viruses can be measured under electron microscope by comparing their size with that of known sized latex particles – o    the poxviruses are measure around 330 × 230 × 100 nm, o    Paramyxo and herpesviruses ranges from 120-300 nm o    Whereas influenza and adenoviruses have diameter of 60-120 nm. o    Smallest viruses are picorna and parvoviruses which measure between 20-40 nm. Ø   Shapes vary – helical (TMV), Icosahedral (Rota virus), bullet shaped (Rabies), oval or spherical. Ø   Helical shape - capsomer coiled around a central axis to form a helical structure. Common...

Introduction          A pH meter is an electronic instrument used for measuring the pH (Acidity or Alkalinity) of a liquid. F Arnold O. Beckman developed the commercial pH meter in 1934. F In  chemistry ,  pH (power of hydrogen) is a numeric scale used to specify the  acidity or  basic  of an  aqueous solution .  F Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are  basic . F Pure water  is neutral, at pH 7 (25 °C), being neither an acid nor a base. F pH measurements are important in  medicine ,  biology ,  chemistry ,  agriculture ,  forestry ,  food science ,  environmental science , oceanography ,  civil engineering ,  chemical engineering ,  nutrition ,  water treatment  and  water purification , as well as in many other applications. F The concept of pH was first introduced...